Protective tape for wire harness

Abstract

To provide a protective tape for a wire harness which has excellent tape winding workability, excellent inhibition of peeling off of a tape edge, and excellent wear resistance.SOLUTION: A protective tape for a wire harness 10 includes a base material 102 and an adhesive layer 104 formed on the base material 102. The base material 102 includes a thermoplastic resin, and is 120-190 μm in thickness,12.5-18.5 in 10% modulus (N / 19 mm width), and 0.8-4.5 in rewinding adhesive force (N / 19 mm width).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a protective tape for a wire harness. [Background technology]

[0002] Patent Document 1 describes a pressure-sensitive adhesive resin tape as a protective tape for wiring harnesses, which comprises a resin substrate and a pressure-sensitive adhesive layer provided thereon, the pressure-sensitive adhesive layer being formed from a pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition is described as comprising 100 parts by mass (non-volatile content) of a base resin made of a mixture of natural rubber latex and synthetic rubber latex, blended with 40 to 120 parts by mass of a rosin-based tackifying resin having a softening point of 130 to 135°C, and 1 to 15 parts by mass of low-molecular-weight polyisoprene having a weight-average molecular weight of 15,000 to 40,000. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-178008 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the wire harness protective tape of Patent Document 1 was unable to improve all of the tape winding workability, the prevention of tape end peeling, and the abrasion resistance in a balanced manner.

[0005] An object of the present invention is to provide a protective tape for a wire harness which is excellent in tape winding workability, prevention of tape end peeling, and abrasion resistance. [Means for solving the problem]

[0006] The protective tape for a wire harness of the present invention has a substrate and an adhesive layer formed on the substrate, and is characterized in that the substrate contains a thermoplastic resin, has a thickness of 120 μm or more and 190 μm or less, a 10% modulus (N / 19 mm width) of 12.5 or more and 18.5 or less, and an unwinding adhesive strength (N / 19 mm width) of 0.8 or more and 4.5 or less. [Effects of the Invention]

[0007] The protective tape for a wire harness of the present invention exhibits the effects of excellent tape winding workability, suppression of tape end peeling, and excellent abrasion resistance. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view of a wire harness protection tape according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a wire harness protection tape according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiment. Furthermore, the components in the following embodiments include those that can be easily imagined by a person skilled in the art or those that are substantially the same.

[0010] [Embodiment] An embodiment will be described with reference to Fig. 1. The embodiment relates to a protective tape for a wire harness. Fig. 1 shows a protective tape for a wire harness according to an embodiment.

[0011] The wire harness protection tape 10 of this embodiment is suitable for use with wire harnesses for automobiles. The wire harness protection tape 10 of this embodiment is used when bundling wire harnesses or when fixing a wire harness protection member to a wire harness. Specifically, it can be used by wrapping it around a bundling position or a fixing position.

[0012] The wire harness protection tape 10 of this embodiment has a substrate 102 and an adhesive layer 104 formed on the substrate 102. The substrate 102 contains a thermoplastic resin and has a thickness of 120 μm or more and 190 μm or less. Furthermore, the 10% modulus (N / 19 mm width) is 12.5 or more and 18.5 or less, and the unwinding adhesive strength (N / 19 mm width) is 0.8 or more and 4.5 or less. The wire harness protection tape 10 of this embodiment can achieve a balanced improvement in all of the tape winding workability, the prevention of tape end peeling, and the abrasion resistance.

[0013] In conventional wire harnesses, thick polyvinyl chloride (PVC) tape or polypropylene (PP) tape with added abrasion resistance has been used to bundle and protect electric wires. One issue with thick tape is that the ends of the tape tend to peel off after bundling. To address this issue, efforts have been made to improve peeling by increasing the tape's unwinding adhesive strength, but this also reduces the ease of tape wrapping when bundling electric wires. Alternatively, the peeled areas have been re-secured with thin tape, but this requires material costs and labor. Therefore, there has been a demand for a tape that does not peel off the ends of the tape and that also allows for good tape wrapping.

[0014] However, if the unwinding adhesive strength is reduced to improve workability during tape winding, tape edge peeling occurs after winding onto the electric wire. Two factors contribute to edge peeling: low adhesive strength and shrinkage of the substrate after the tape is peeled off. Therefore, the inventors discovered that, because excessive adhesive strength places a heavy burden on the operator, it is necessary to use a substrate that is not too adhesive and is resistant to shrinkage (deformation). Furthermore, by exploring the ranges of the tape's 10% modulus, unwinding adhesive strength, and substrate thickness, the inventors discovered that a tape that does not experience edge peeling, has good tape winding workability, and is also excellent in abrasion resistance can be obtained.

[0015] In other words, the substrate 102 is a film made of a thermoplastic resin. As the thermoplastic resin, at least one selected from the group consisting of polyvinyl chloride (PVC), polypropylene, and polyethylene is preferably used. Among these, polyvinyl chloride is more preferably used.

[0016] The adhesive layer 104 is typically formed from an adhesive composition. Examples of the base material of the adhesive composition include rubber-based natural rubber latexes such as unmodified natural rubber latex and acrylic-modified natural rubber latex, and acrylic polymers. Specifically, from the viewpoint of unwinding adhesive strength, at least one selected from the group consisting of unmodified natural rubber latex, acrylic-modified natural rubber latex, and acrylic polymers is preferably used. In addition to the base material, known additives can be blended into the adhesive composition as needed. Examples of additives include tackifying resins such as rosin ester resins, terpene resins, and aliphatic and aromatic hydrocarbon resins; softeners such as low-molecular-weight isoprene rubber (IR) and polyisobutylene; and antioxidants such as phenolic antioxidants.

[0017] The adhesive layer 104 is formed on the substrate 102 by a known method. For example, an adhesive composition is applied to the substrate 102 using various coaters and then dried to form the adhesive layer. Separately, an adhesive layer may be formed on a separator and then transferred onto the substrate 102. Therefore, in the obtained wire harness protection tape 10 of the present embodiment, the adhesive layer 104 contains natural rubber latex and an acrylic polymer. Specifically, from the viewpoint of unwinding adhesive strength, the adhesive layer 104 contains at least one selected from the group consisting of unmodified natural rubber latex, acrylic-modified natural rubber latex, and an acrylic polymer. The adhesive layer 104 preferably has a thickness (glue thickness) of 5 μm or more and 50 μm or less.

[0018] The 10% modulus and unwind adhesive strength of the wire harness protection tape 10 of this embodiment can be controlled by appropriately adjusting the types, blending ratios, and thicknesses of the raw material components of the substrate 102 and adhesive layer 104.

[0019] The wire harness protection tape 10 of this embodiment may include layers other than the substrate 102 and the adhesive layer 104, if necessary. For example, a primer layer such as a nitrile rubber (NBR)-based primer layer may be provided between the substrate 102 and the adhesive layer 104. By providing the primer layer, the adhesion of the adhesive layer 104 to the substrate 102 can be improved.

[0020] [Example] The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0021] [Example 1] A nitrile rubber (NBR) primer layer and a rubber-based adhesive layer were formed on a 140 μm-thick polyvinyl chloride (PVC) substrate to obtain a wire harness protection tape. Specifically, the adhesive layer contained unmodified natural rubber latex and acrylic-modified natural rubber latex, and its thickness was in the range of 5 μm to 50 μm. The 10% modulus (N / 19 mm width) and unwound adhesive strength (N / 19 mm width) of the obtained wire harness protection tape 10 are shown in Table 1.

[0022] [Examples 2 to 6] A primer layer and an adhesive layer were formed on the substrate in the same manner as in Example 1, except that the thickness of the polyvinyl chloride (PVC)-containing substrate, the blending ratio of the main agent in the adhesive layer, and the thickness of the adhesive layer were appropriately changed, to obtain a wire harness protective tape. The thickness of the adhesive layer was in the range of 5 μm to 50 μm. The 10% modulus (N / 19 mm width) and unwound adhesive strength (N / 19 mm width) of the obtained wire harness protective tape 10 are also shown in Table 1.

[0023] [Comparative Examples 1 to 5] A primer layer and an adhesive layer were formed on the substrate in the same manner as in Example 1, except that the thickness of the polyvinyl chloride (PVC)-containing substrate, the blending ratio of the main agent in the adhesive layer, and the thickness of the adhesive layer were appropriately changed, to obtain a wire harness protective tape. The thickness of the adhesive layer was in the range of 5 μm to 50 μm. The 10% modulus (N / 19 mm width) and unwound adhesive strength (N / 19 mm width) of the obtained wire harness protective tape 10 are also shown in Table 1.

[0024] [Measurement method] [Tensile test (10% modulus)] In accordance with JIS Z 0237, a protective tape for wire harnesses (tape width 19 mm) was peeled off at a speed of 5 mm / s using a tensile tester with a chuck grip distance of 100 mm. After peeling, the strength was read when the tape had stretched 10 mm (10%).

[0025] [Slow unwinding adhesive strength] Using a tensile tester in accordance with JIS Z 0237, a roll of wire harness protection tape was fitted into the roller of a mounting jig and peeled off at a speed of 5 mm / s. Measurements were taken at three points: 40 mm, 60 mm, and 80 mm, and the average value of the three points was calculated.

[0026] [Thickness] According to JIS C 2107, five 19 mm wide test pieces were cut from the roll using a dial gauge, and after leaving them for at least 5 minutes to remove strain, the upper surface of the gauge was gently lowered onto the surface of the test piece, and the minimum value was read. The thickness of the substrate containing polyvinyl chloride (PVC) was also measured in advance in the same manner as above. The thickness of the adhesive layer was then obtained by subtracting the thickness of the substrate from the minimum value read for the test piece.

[0027] [Evaluation method] [Workability judgment] Based on the results of measuring the adhesive strength at low unwinding speed, the evaluation was made according to the following criteria. ○: 0.8N / 19mm width or more, 4.5N / 19mm width or less ×: Less than 0.8N / 19mm width or more than 4.5N / 19mm width

[0028] [Terminal peeling] A wire harness protection tape was wrapped around a bundle of wires with a diameter of 10 mm, and then the bundle was left at 80°C for 4 hours. After that, peeling of the tape at the end was checked. ○: Peeling of less than 1 mm was observed. ×: Peeling of 1 mm or more was observed.

[0029] [Wear resistance] Two test pieces (protective tape for wire harnesses) of an appropriate length were attached to a φ10 mm aluminum pipe, overlapping each other (double-layered), and then set in an abrasion resistance tester specified in JASO D 608, and a load of 4.4 N was applied to the test pieces. The abrasion tape was then moved at a speed of 1500 mm / min, and the length of the tape until it came into contact with the aluminum pipe was read. ◎: 450mm or more ○: 300mm or more and less than 450mm ×: Less than 300mm

[0030] [Table 1] [Explanation of symbols]

[0031] 10: Wire harness protection tape 102: Base material 104: Adhesive layer

Claims

1. A substrate and a pressure-sensitive adhesive layer formed on the substrate, the substrate contains a thermoplastic resin and has a thickness of 120 μm or more and 190 μm or less; The 10% modulus (N / 19 mm width) is 12.5 or more and 18.5 or less, The unwound adhesive strength (N / 19 mm width) is 0.8 or more and 4.5 or less. A protective tape for a wire harness, characterized in that

2. The thermoplastic resin is at least one selected from the group consisting of polyvinyl chloride, polypropylene, and polyethylene. The wire harness protection tape according to claim 1 .

3. The pressure-sensitive adhesive layer contains at least one selected from the group consisting of unmodified natural rubber latex, acrylic-modified natural rubber latex, and acrylic polymers. The wire harness protective tape according to claim 1 or 2.

4. The pressure-sensitive adhesive layer has a thickness of 5 μm or more and 50 μm or less. The wire harness protective tape according to claim 1 or 2.

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